The invention set forth in this specification pertains to new and improved dental implants.
The development of various biocompatible materials has resulted in a resurgence of interest in the development of dental implants. This in turn has led to the development of a wide variety of implant structures of various shapes and materials for use as replacements for natural teeth. An understanding of the present invention does not require a discussion of the various different structures which have been proposed and to some extent used as dental implants or of the various ways they have been used.
From a review of such prior implant structures it is possible to conclude that a number of factors have tended to restrict their widespread use. These include ease of insertion of an implant member, especially in those cases where the alveolar cavity to receive the implant does not precisely correspond to that of the implant. A related consideration concerns the need for an acceptable implant to fit with respect to the cortical portion of a jawbone so as to prevent soft tissue from invading the interior or medullary region of the jawbone as the implant remains in place after being installed in the jawbone.
The "holding" characteristics of an implant are also important to the acceptability of such a member. Critical questions relative to such characteristics are whether the shape of the implant will adequately engage the inner medullary portion within the outer or cortical portion of a jawbone to a sufficient extent that the implant will be held permanently in place. To be acceptable it also needs to be held in such a manner that the stresses and strains placed upon it during chewing are distributed in such a way as to minimize the chances of discomfort.
Another factor which is considered to have tended to restrict the use of prior implants relates to the mounting of a crown prosthesis upon them after they have been installed. In general the prior structures have normally been of such a character that there has been only one manner that a "tooth" or crown prosthesis could be mounted upon them. While this is frequently satisfactory, on occasion it is not desirable because of differing views as to the most desirable way of mounting a prosthesis.